SYNTHESIS OF FLUORINATED TELOMERS .2. TELOMERIZATION OF TRIFLUOROETHYLENE WITH PERFLUOROALKYL IODIDES

The synthesis of highly fluorinated telomers by thermal telomerization of trifluoroethylene with branched (i-C3F7I, C5F11CFICF3) or linear (C4F9I, C4F9CH2CF2I) fluoroalkyl iodides is presented. All these telomerizations led to the first three telomeric adducts with high R(F)I conversion. Interestingly, the monoadduct was composed of two isomers R(F)CF(2)CFHI (1) and R(F)CFHCF(2)I (2), the ratio of which depends upon the electrophilicity of the radical R(F.). The more electrophilic this radical, the higher the amount of isomer 2, according to a mechanism that responds to both the polar and the mesomeric effects for growing radicals.